JPS5932280B2 - cutting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an apparatus for cutting pieces from a strip of material advanced by feed rollers, the strip of material being cut into pieces on cutting cylinders which are interconnected by helical gears. The present invention relates to a device having a helical cutting blade arranged transversely to the other, and in which at least one of the cutting cylinders is mounted for axial displacement.

Devices for cutting pieces from a strip of material fed by feed rollers can be used, for example, in machines for manufacturing bags or bags, for cutting bag pieces from tubular material or from strips of cover sheet material. The cover sheet that is to become the bottom of the box is cut out.

In bag and bag making machines, the folded bottom is often finished with a cover sheet, which is superimposed in place and may be printed to indicate the contents or origin of the bag. Furthermore, the side walls of the bag are also printed. During production, disruptions occur in the machine if the bag segments that are continuously fed at a constant rate are interrupted, or if some bags have to be removed due to failures or blockages. In this case, the supply of the cover sheet, which is to become the bottom, must also be interrupted. Otherwise, the presence of a cover sheet for the missing bag would cause even more confusion. Interrupting the cover sheet supply is typically accomplished by removing the feed roller from the drive source after the last desired cover sheet has been cut from the web. High speed machines have the disadvantage that the cover sheet strip continues to be fed even after the feed rollers have been removed. This is due to the inertia of the feed roller drive components and the feed roller itself. As a result, the leading edge of the cover sheet strip is still moving and projects beyond the cutting line between the cutting cylinders. The cutting cylinder continues to rotate, so that the protruding part of the strip is unintentionally cut off and the scraps must be sucked out or removed.

This unintentional cutting from the leading edge of the strip means that the next cover sheet to be cut from the strip in the next normal operation will be too short, and this cover sheet must be pre-attached to the bag piece to be overlapped. The applied molten adhesive cannot be sufficiently covered. Exposed adhesive will cause sticking problems in subsequent steps.
Clearly, therefore, the fact that the feed roller for the cover sheet strip continues to rotate even after you have intended to stop it creates problems with retention, and these problems occur when the cover sheet material is printed. If it is, it becomes even more difficult. German Patent Specification No. 81423
In the cutting device known from No. 6, one or both cutting cylinders are displaced across the web during the actual cutting operation, thereby preventing the web from deviating from its path.

This axial displacement of the cutting cylinder is effected by cam control, using helical gears which ensure that the helical cutting blades do not separate from each other during the cutting operation. However, unintentional or unauthorized cutting of the strip is unavoidable with such known devices when the strip feed is interrupted.It is an object of the present invention to ensure that even when stopping and refeeding the strip, An object of the present invention is to provide a cutting device that can reliably avoid incorrect cutting and can correctly cut pieces of a desired length from a strip material.

According to the invention, the device for cutting off pieces from the web fed by the feed roller is arranged transversely to the web on cutting cylinders interconnected by helical gears. a helical cutting blade, at least one of the cutting cylinders being mounted for axial displacement, and a feed roller being removable from the drive by a single tooth dog clutch; a cutting cylinder is positively connected to the drive part, and the at least one cutting cylinder is axially displaced in a direction to separate the cutting blades when the feed roller is disengaged from the drive part, and the feed roller is connected to the drive part. A device is provided for returning the cutting cylinder to a state in which the blade can be cut when engaged.

The single-tooth dog clutch allows the feed roller, when engaged, to reliably and correctly advance the web toward the cutting blade, which continues to rotate even when the feed roller is at rest.

However, due to the axial displacement, the cutting blade is rendered inactive upon disengagement of the feed roller. The cutting cylinder is securely connected to the drive unit and the feed roller (or each feed roller if more than one is used)
can be reconnected precisely to the drive, so that even if there is an interruption in the supply of the web to the cutting cylinder, the web will be cut in the correct position. Therefore, when interrupting production, all that is required is to remove the feed roller advancing the web from the drive. Therefore, there is no need to brake the acceleration of the cutting cylinder and other components. DE 21 22 071 discloses a strip cutting device in which a stationary cutting blade is rotated about its longitudinal axis in order to separate the mating blade from the mating blade. The use of stationary cutting blades to cut rapidly moving webs is problematic, especially when the webs are plastic films. The invention has been developed specifically for a device for cutting plastic film. Furthermore, confusion tends to occur when using a fixed blade to cut adhesive coated strips. Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

A pretreated strip 1 coated with adhesive is fed through a deflection roll 2 to a feed roller 3 .

This feed roller is a suction roller. That is,
It has a number of radial orifices on its circumferential surface, which communicate with a suction pump (not shown) so that a suction effect is produced on what is covered by the strip 1. Due to the suction effect of the roller 3, the strip 1 is held on the circumferential surface of this roller and is fed as it rotates. Below the feed roller 3, there is a strip material 1 that has been fed.
A guide plate 4 is provided for this purpose. The imaginary extension of the guide plate 4 includes two cutting cylinders 10, 1 with blades 12, 13 extending parallel to the blade axis.
It intersects with the cutting line 9 of 1. The upper part of the circumferential surface of the cutting cylinder 11 when viewed in the rotational direction forms a suction surface 14 with orifices 15 arranged side by side in the circumferential direction and one behind the other in the axial direction. has been done. Orifice 15 communicates with a suction pump (not shown). A piece 16 cut from the strip 1 along the cutting line 9 is held by this suction surface 14 . The guide plate 4 is rotated by the rotating guide plate 19.
The fragments 16 which are suspended from and enter the circle in which the suction surface 14 is located are held at intervals corresponding to the curvature of the suction surface 14. A conveyor 17 is provided below the cutting cylinder 11 for conveying the bag pieces 18 in synchronization with the rotation of the cutting cylinder 11, which transports the cut pieces 16 into the bag pieces 1.
It is intended to be attached to 8. The piece 16 is carried by the cylinder 11 through a quarter turn and is placed on the bag piece 18 in the correct position. As can be seen with reference to FIG. 2, there are three feed rollers, a cutting cylinder 10,
11 is rotatably attached to the walls 20, 21 of the frame.

A gear 22 is rotatably supported on the shaft 3,1 of the feed roller 3, and a single-tooth dog clutch 23 is mounted longitudinally displaceably on this shaft. By key 24,
The dog clutch 23 is capable of transmitting torque to the shaft 3,1.
This clutch has a radial groove 25 in which the lever 26 engages.
The lever 26 is adapted to rotate around a shaft 27. A finger piece 28 is attached to one end of the dog clutch 23.
, and this finger piece is an abutment piece 29 fixed to the gear 22.
, thereby transmitting the torque transmitted by gear 22 to dog clutch 23.
The surface of the dog clutch is a conical braking surface 30. This braking surface engages a conical braking surface provided on the bracket 31 of the wall 20 at a suitable displacement position of the dog clutch 23. By rotating the lever 26 into one end position, the shaft 3,1 is braked under the cooperation of the bracket 31 of the braking surface 30, and this lever can be rotated into the other end position. Therefore, this shaft 3,1 is the finger piece 2
8 and an abutment piece 29 by means of a gear 22. The gear 22 meshes with a gear 33 via an intermediate gear 32 or a variable speed gear mechanism in order to match the width of the cover sheet to be cut from the strip.
It is a sliding fit on the hollow shaft 11.1 of the cutting cylinder 11.

Gear 33 is driven by the main drive of the machine. The hollow shaft 11.1 accommodates a rod 11.2 which is connected at one end to the gearwheel 33 by a key 34 and an intermediate member 35. The other end of the rod 11.2 is provided with a flange 36 which is screwed into a handle 37 which is clamped to the hollow shaft 11.1.
They are removably connected by. By loosening the screw 38, the handle 37 can be rotated relative to the flange 36. Thereby, the cutting cylinder 11
can be varied relative to the drive, for example gear 33. One end of the cutting cylinder 11 is connected to a suction conduit 40
A plate 39 is provided.

This conduit 40 communicates with the orifice 15 of the cutting cylinder 11 through an annular passage 41 . The plate 39 is a sliding fit on the boss-shaped extension 42 of the cutting cylinder 11 and is secured against rotation by bolts 43 on the frame. The annular channel 41 is configured in such a way that the fragment 16 is held against the suction surface 14 during the cutting operation and is pressed onto the bag fragment 18 when the cutting cylinder 11 is rotated a quarter turn. Cutting cylinder 11
A gear 44 connected to the cutting cylinder 10 meshes with a gear 45 fixed to the cutting cylinder 10.

Both gears are helical gears. Gear 45 is wider than gear 44. The shaft 10.1 of the cutting cylinder 10 is displaceably mounted in the wall 21 of the frame. The journal of the roller bearing 46 is longer than its width. This journal is held in a bushing 47 fixed to the frame. Upon axial displacement of the shaft 10.1, the rollers move beyond the journal. The roller bearing 48 is connected to the shaft 10.
1 and a bushing 49 which can be axially displaced at the wall 20 by means of a pressure cylinder 50 supported on the frame.

This displacement is limited by the base of the hole in the wall 20 which receives the abutment piece 51 and the bushing 49. The blades 12, 13 of the cutting cylinders 10, 11 can be removed by actuating the pressure cylinder 50.

This is because the longitudinal displacement of the cutting cylinder 10 due to the helical gears 44, 45 causes it to rotate by an amount corresponding to the helical angle of the gears, so that the edges of the blades 12, 13 no longer simultaneously cut the cutting line 9. This is because it will not pass through. The pressure cylinder 50 is controlled in synchronization with the rotation of the lever 26, so that when the feed roller 3 is disengaged, the cutting cylinders 10, 11 are also disengaged.

Even if the feed roller 3 continues to rotate in the high-speed machine despite the braking force applied to the control surface 30, the tip of the strip 1 is kept in contact with the continuously rotating cutting cylinders 10, 1.
1 has left, so it will not be disconnected. When the feed roller 3 is reconnected to the drive, the fingers 28 ensure that the feed roller 3 is reconnected to the drive in the same position as when it was disconnected, so that the cutting cylinders 10, 1
1 is also reconnected at the same position. During a new rotation of the feed roller 3, the blades 12, 13 of the cutting cylinders 10, 11 will also mesh again, so that
The next piece 16 is cut from the strip 1 in the correct position.
The present invention has the following embodiments. (1) The device of claim 1, wherein the surface of the dog clutch is a conical braking surface that engages a braking surface of a bracket secured to the frame.

(2) A device as claimed in claim 1, in which one of the cutting cylinders is adjustable with respect to the drive gear by a handle acting through the flange, the rod and the intermediate member. (3)
Apparatus according to claim 1, wherein the displacement device includes a pressure cylinder acting on a bushing and a roller bearing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of the cutting device, and FIG. 2 is a sectional view taken along the line - in FIG. 1. DESCRIPTION OF SYMBOLS 1... Strip material, 3... Feed roller, 4... Guide plate, 9... Cutting line, 10, 11... Cutting cylinder, 12, 13... Blade, 14... Suction Surface, 15... Orifice, 16... Fragment, 22.
... Gear, 23 ... Dog clutch, 26 ... Lever, 30 ... Conical braking surface, 31 ... Bracket,
33... Gear, 37... Handle, 38... Screw, 40... Conduit, 44, 45... Gear, 46...
Roller bearing, 47... Bushing, 48... Roller bearing, 49... Bushing, 50... Pressure cylinder.

Claims (1)

[Claims] 1 A device for cutting pieces from a strip of material fed by a feed roller, with a helical shape disposed transversely to the strip on cutting cylinders interconnected by helical gears. a cutting device including a cutting blade, and in which at least one cutting cylinder is mounted for axial displacement, a single-tooth dog clutch for engaging and disengaging the feed roller from the drive; a cutting cylinder is positively coupled to a drive, and further axially displacing at least one cutting cylinder to separate the cutting blade when the feed roller is removed from the drive; The cutting device further includes a device for returning the displaced cutting cylinder to return the cutting blade to the cutting state when the feed roller is connected to the drive unit.